Simplify the following expression: $k = \dfrac{2r^2}{pr - 5r} + \dfrac{3r^2 + 4pr}{pr - 5r}$ You can assume $p,q,r \neq 0$.
Solution: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{2r^2 + 3r^2 + 4pr}{pr - 5r}$ $k = \dfrac{5r^2 + 4pr}{pr - 5r}$ The numerator and denominator have a common factor of $r$, so we can simplify $k = \dfrac{5r + 4p}{p - 5}$